Straight bar knitting machines



May 3, 1966 coP o 3,248,903

STRAIGHT BAR KNITTING MACHINES Filed Sept. 27, 1965 14 Sheets-Sheet l H -5 a \r 2 N j 7 5 3 fi 91 I E\ N a I! Q N g "a "a Q N Q s n N N 1 T N Q 3 3 a ag 2 Q May 3, 1966 A. COPPO I 3,248,903

, STRAIGHT BAR KNITTING MACHINES Filed Sept. 27, 1963 14 Sheets-Sheet 2 l4 Sheets-Sheet 5 Filed Sept. 27, 1965 y 1966 A. COFPO 3,248,903

STRAIGHT BAR KNITTING MACHINES Filed Sept. 27, 1963 14 Sheets-Sheet 4 Fig.4

May 3, 1966 A. coPPo STRAIGHT BAR KNITTING MACH INES 14 Sheets-Sheet 5 Filed Sept. 27, 1963 A. COPPO May 3, 1966 STRAIGHT BAR KNITTING MACHINES l4 Sheets-Sheet 6 Filed Sept. 2'7, 1963 May 3, 1966 A. COPPO 3,248,903

STRAIGHT BAR KNITTING MACHINES Filed Sept. 27, 1965 14 Sheets-Sheet 7 May 3, 11966 A. coPPo STRAIGHT BAR KNITTING MACHINES 14 Sheets-Sheet 8 Filed Sept. 27, 1963 May 3, 1966 A. coPPo STRAIGHT BAR KNITTING MACHINES 14 Sheets-Sheet 9 Filed Sept. 27, 1963 May 3, 1966 A.' coPPo STRAIGHT BAR KNITTING MACHINES l4 Sheets-Sheet 10 Filed Sept. 27, 1963 14 Sheets-Sheet 11 Q .3 mm RQQ Q @838 mm b N Ill.- y m N T v II I -MHM l/ b 3 my iiafl g8 M. 8 Q 3 Q May 3; 1966 COPPO STRAIGHT BAR KNITTING MACHINES Filed Sept. 27, 1963 May 3, 1966 A. COPPO STRAIGHT BAR KNITTING MACHINES 14 Sheets-Sheet 12 Filed Sept. 27, 1963 A. COPPO STRAIGHT BAR KNITTING MACHINES May 3 1966 14 Sheets-Sheet 13 Filed Sept. 27, 1963 y 1966 A. COFPO 3,248,903

STRAIGHT BAR KNITTING MACHINES Filed Sept. 2'7, 1963 14 Sheets-Sheet 14 Fig.23

United States Patent 3,248,903 STRAIGHT BAR KNITTING MACHINES Alessandro Coppo, 44 Via Antonelli, Regina Margherita (Turin), Italy Filed Sept. 27, 1963, Ser. No. 312,072 6 Claims. (Cl. 66--70) This invention relates to a device for automatically reducing and increasing the number of operating needles and shifting the rear needle bed on straight bar knitting machines in order to perform a fully automatic operational cycle of the machine.

The improved device comprises two pairs of reducing units arranged near the needle bed ends, which are operated in accordance with the timing program in order to take oif a given number of loops from the needles and move them towards the center by at least one pitch. The members provided for controlling the reducing units moreover control the increase in number of the operating needles and shifting of the forward needle bed.

The reducing units each comprises a number of points and a cam which are movable towards and away from the needles in a transverse direction and are moreover movable in a longitudinal direction for shifting the loops along the needle beds. The points are formed with eyelets for engaging the top hooks on the needles and move them up and down in order to take off the loops.

Further characteristic features of this invention will be understood from the appended detailed description referring to the accompanying drawings which show an embodiment thereof by way of example.

FIGURES 1 and 2 show diagrammatically the left-hand and right-hand end, respectively, of the top portion of a straight bar knitting machine equipped with the improved device;

FIGURES 3 and 4 are plan views of FIGURES 1 and 2, respectively;

FIGURE 5 is a perspective view of a reducing unit;

FIGURES 6 to show a reducing unit in its successive operating positions during a reduction in number of the operating needles;

FIGURE 16 is a diagrammatical plan view of a reducing unit;

FIGURE 17 is a part sectional elevational view of a reducing unit;

FIGURE 18 is a diagram showing the control mechanisms for the reducing units, for increasing of operating needles and for shifting the rear needle bed, and

FIGURES 19, and 21 show details of FIGURE 18.

FIGURE 22 is a sectional view on line XXIIXXII of FIGURE 18;

, FIGURE 23 is a sectional View on line XXIIIXXIII of FIGURE 22, and

FIGURE 24 is a detailed view of FIGURE 23.

A carriage 2 is movable along longitudinal guides 1 on a straight bar knitting machine, of which the forward and rear needle beds 3, 4, respectively (FIGURE 2 and FIGURES 6-15), are formed with cross grooves in which needles 5 are slidable. The needles 5 (FIGURE 6) are provided with a top hook 5a which can be closed or opened, respectively, by a latch 5b at which the loops of the knitted fabric are formed.

Near each needle bed is arranged a set of coaxial longitudinal tubular bars. The innermost bar 6 (FIGURE 5) extends throughout the machine length and acts as a connecting member in a manner which will be explained below. The intermediate bar 7 likewise extends throughout the machine length and is formed with a longitudinal notch 7a, the length of which equals that of the needle bed. Each portion of the bar 7 extending beyond the needle bed is surrounded by a tubular bar 8 splined on 3,248,983 Patented May 3, 1966 the outside and having slidably but not rotatably mounted thereon a sleeve 9.

Each sleeve 9 has attached thereto a holder 10 for a needle reducing unit. The machine is therefore equipped with two pairs of reducing units 10 arranged on the left and right, respectively, of the two needle beds and slidable along the bars 8.

The reducing units are each provided with a main slide 11 (FIGURE 17) carrying a forward plate 12 having secured thereto a set of points 13 spaced similarly to the needles and formed with slits 13a of a width such as to encircle the needle hooks.

The slide 11 is provided with a lower rack 11a meshing with a pinion 14 coupled with the tubular bar 7 by means of a stud 15 acting as a cotter. The pinion 14 is fast in rotation with the tubular bar 7 and is capable of axial displacement relative thereto.

The reducing units are each provided with a top slide 16 carrying a sinker bar 17 the spikes 17a of which are normally turned towards the points 13 and lit into the spaces between the points.

The top slide 16 is formed with a slot 16a guided about a pin 18 carried by the main slide 11. The pin 18 causes the top slide 16 to move forward together with the bottom slide 11 after the latter has been shifted independently a certain length.

The plate 12 carried by the lower slide 11 is moreover provided with a pivot 19 for a pawl 20 arranged in parallel relationship with the points 13. The pawl 20 is restored by a spring 21 which normally is held in contact with a stop 22 on the plate 12.

The reducing units 10 are each connected by a nut 23 (FIGURE 18) carried by the sleeve 9 to a longitudinal screw 24 which feeds the reducing unit in a longitudinal direction.

The reducing units therefore perform a rocking movement about the axis of the tubular bars as a result of oscillation of the bars 8 and a longitudinal translational movement along the bar axis under the action of the screws 24 (FIGURES 1-4 and 18). The slides 11, 16 carrying the points 13 and sinker bar 17, respectively, are moved transversely as a result of rotation of the bar 7 and pinion 14.

FIGURES 6 to 15 show operation of a reducing unit during a needle reducing step. 1

In their inoperative condition the points 13 and sinker bar 17 are in a receded position, the holder 10 being lifted to an angle other than in its operative condition (FIG- URE 6) to clear the needle hooks and carriage 2. The holder 10 is initially swung in the direction indicated by the arrow in FIGURE 7 by its splined bar 8, the points 13 and sinker bar 17 simultaneously performing a forward movement, the points fitting by their slots 13a on the needle bits 5a and the spikes in the sinker bar 17 within the gap between the two needle beds in front of the needle bits (FIGURE 7).

The support 10 is now moved to its lowermost position by a further swinging motion of the splined bar 8 to engage the slits 13a in the points by the needle hooks 5a (FIGURE 8).

While the sinker bar is stationary the points 13 recede thereby lifting the needles and knocking the loops beneath the needle latches 5b (FIGURE 9). The spikes in the sinker bar 17 are maintained in their position and prevent yarn from rising together with the needle, the yarn being accurately positioned beneath the needle latches.

The points 13 move forward thereby transferring the loops from the needles onto the points (FIGURE 10).

The holder 10 is now slightly lifted by swinging in the direction indicated by the arrow in FIGURE 11, releases the points from the needle bits and is subsequently moved forward in an axial direction by one or more pitches carrying along the loops on the points.

On reaching its fresh position in a longitudinal direction the holder sinks in the direction indicated by the arrow in FIGURE 12 and again causes the slits in the points to engage the needle hook-s in a position displaced by one or more pitches (FIGURE 12). The points 13 recede thereby transferring the loops to the needle hooks in a position displaced by one or more pitches with respect to their preceding position (FIGURE 13).

The spikes in the sinker bar assist transfer of the loops by maintaining the latter constantly equally spaced from the needle beds.

The points 13 are fed forward thereby moving the needles downward to their operative position. The lateral pawl 20 acts on the needle from which a loop has been transferred to sink it to its inoperative position (FIG- URE 14), whereupon the unit is lifted and the points and sinker bar recede from the position shown in FIGURE 15 to their inoperative position shown in FIGURE 6.

FIGURES 18 to 22 diagrammatically show the controls for the various movements on the previously described reducing units.

To this end the shafts 2% are each controlled by a driving mechanism (see FIGS. 22 to 24) comprising a disc 30 formed with an internal set of teeth 30a, fast with a Wormwheel 31 loosely mounted on the shaft 29 and a bridge piece 32 carried by a sleeve 61 secured to the shaft 29. The bridge piece 32 is guided with respect to screws 62 for transverse displacement with respect to the sleeve 61 and disc 30 and is formed with a set of teeth 32a for engagement with the internal set of teeth 30a in the disc 30. Since the bridge piece is angularly linked to the shaft 29, it securely connects the latter with the driving worm wheel 31 when its set of teeth 32a meshes with the set of teeth in the disc 30. This engagement is effected by a pair of springs 63 acting on the bridge piece.

Laterally of each disc 3Gbridge piece 32 unit a pawl 64 (FIGURE 22) is mounted for oscillating about a pivot 65 and is urged by a spring 66 tending to maintain roller 67 mounted on the pawl end in contact with a slidable rod 68.

The rod 68 is linked at the top to a movable core 69 of an electromagnet 70 associated with the members of the automatic cycle and is urged back at its bottom by an opposing spring 71. The rod 68 is formed with a lateral projection 68a adapted to cooperate to the roller 67 on the swinging pawl.

In the inoperative condition the roller 33 on the bridge piece 32 is in its opposition indicated by dash-lines in FIG. 22, and bears against the pawl 64, the roller of which bears in turn on the projection 68a of the rod 63.

In order to effect a reduction the electromagnet 70 instantaneously lifts the rod 68 causing the spring 66 to swing the pawl 64 which no longer bears on the projections 68a. Consequently, the bridge piece 32 released from the pawl 64 moves under the action of the springs 63 its set of teeth 32a into mesh with the internal set of teeth 30a in the disc 30. This starts rotation of the shaft 29 which is pursued exactly over one revolution, on completion of which the roller 33 on the bridge piece 32 again abuts the pawl 64 which has been returned to its normal position abutting the projection 68a on the rod 68 on deenergization of the electromagnet 70.

On the left side of the machine are placed two sets of three cams each denoted by 26, 27 and 28 (FIGURE 18) mounted on shafts 29, controlling the longitudinal bars having the two pairs of reducing units mounted thereon.

The sets of cams 26, 27 and 28 perform one full turn on each reducing step. I

The worm wheel 31 is moved by a worm screw 34 mounted on a cross shaft 35 which is driven through a bevel gear 36 (FIGURE 18) from a driving pulley 37.

The cam 26 (see FIGURE 19) effects displacement of a small vertical cylinder 38 formed with a set of teeth 39 meshing with a pinion 40 keyed to the end of the tubular bar 7.

The cam 27 (see FIGURE 20) effects on each revolution closure of a microswitch 41 for the purpose explained hereafter, the cam 28 (see FIGURE 21) effecting angular movement of a lever 42 fast with a pinion 43 (FIG- URE 18) keyed to the left-hand portion of the externally splined shaft 8 to oscillate the shaft 8. This oscillation is transmitted to the right-hand shaft 8 through the innermost coupling bar 6 and dog clutches 43-44, 45-46 arranged on the left and similar dog clutches arranged on the right side of the machine.

The screws 24 feeding the reducing units receive movement from mechanisms enclosed by two boxes 47 (FIG- URE 18) arranged intermediate of the machine. The mechanisms include a set of gears receiving motion from the driving pulleys 37 and effecting rotation in one direction or the other direction of shafts 49 and through two clutches 48, respectively. The clutches 48 which are normally uncoupled and do not transmit motion to the shafts 49, 50 are operated in one direction by microswitches 41 acting on electromagnets 41a (FIGURES 1 to 4) and in the other direction by electromagnets 41b and are maintained in their closed position to the left or to the right during one revolution only, whereafter they resume their middle unclutched position.

The shafts 49 drive the screws 24 through bevel gears 51, 52, the shafts 50 effecting in a manner known, but not necessary to an understanding of the present invention, the throwing in of more needles.

The left-hand box 47 incorporates a power take-off driving a shaft 53 reaching into a box 54 provided in the middle of the machine. The box 54 encloses a clutch 55 transmitting motion to a device 56 of known construction for shifting the rear needle bed.

The two forward screws 24 feeding the reducing units carry nuts 57 fast with cams 58 adapted to uncouple the thread-guides.

The cams 58 perform movements directed inwardly and towards the ends of the machine together with the needle selecting units, whereby the operating thread-guide is constantly equally spaced from the last operative needle.

What I claim is:

1. In a fiat bed knitting machine having a stationary frame and at least one needle bed, an automatic decreasing device comprising for each bed a first tubular bar rotatably mounted in said stationary frame near the opposite ends of the latter, said first tubular bar extending throughout the machine length and being parallel to the needle bed and arranged with its axis lying substantially in the plane of the needle bed and spaced from the top edge of the latter, a pair of tubular bars externally splined each surrounding a portion of said first bar extending beyond the needle bed and rotatably mounted in the machine frame, a pair of sleeves each mounted axially movable but not rotatably on one of said splined bars, a pair of oppositely threaded screws parallel to said bars each extending substantially over the length of one of said splined bars, a holder carrying a needle reducing unit attached to the end of each sleeve facing the crossmiddle plane of the machine and a nut fast with said sleeve and engaging one of said screws, each of said needle reducing units carried by said holder comprising a supporting structure carried by said holder and capable of displacement in a direction perpendicular to the common axis of said sleeve and of said bars, a set of points carried by said supporting structure, driving means for rotating said first tubular shaft, said splined shafts and said threaded shafts at proper times, in proper sequence in a proper direction and by a proper angular extent in order to take up the loops from a number of needles and transfer said loops to an equal number of needles shifted with respect to said first-mentioned needles towards the machine middle cross plane.

2. In a machine as set forth in claim 1, said means for rotating said first tubular bar and said splined bars comprising a cam supporting shaft rotatably mounted in the machine frame parallel to said bars, a first and a second cam fast with said shaft, a pinion keyed to said first tubular bar, an axially movable vertical cylinder abutting by its one end the periphery of said first cam and having formed therein a rack engaging said pinion, a lever keyed to one splined bar arranged near said cams abutting by its free end the periphery of said second cam and biased thereagainst by spring means for driving the other splined bar simultaneously with said one splined bar, a constantly rotating member bearing on said cam supporting shaft, normally disengaged coupling means adapted to connect said rotating member with said camshaft, an electromagnet and control means actuated by the latter for engaging the coupling and maintaining it engaged over the period during which the camshaft performs one revolution and means for disengaging the coupling after one complete revolution of the camshaft.

3. In a machine as set forth in claim 2, the means for driving said other splined bar simultaneously with said one splined bar arranged near the cams comprises a rotatably mounted inner bar extending throughout the machine length, arranged inside said first tubular bar and having its opposite ends protruding from the latter, a gearing for transmitting rotation from said splined ba-r arranged near the cams to said inner bar and a gearing for transmitting rotation from said inner bar to the other of said splined bars.

4. In a machine as set forth in claim 2, the driving means for rotating said threaded shafts comprising a third cam fast with said cam supporting shaft, a normally open switch capable of being closed upon rotation of said third cam, a motor-driven shaft for each of said threaded shafts, a transmission interposed between each of said motor-driven threaded shafts and a normally open coupling in each of said transmissions and electromagnetic means excited by the closure of the above mentioned switch for temporarily closing said coupling during the time required for one revolution only.

5. In a flat bed knitting machine having a stationary frame and at least one needle bed therein, an automatic decreasing device comprising for each bed a first tubular bar rotatably mounted in said stationary frame near the opposite ends of the latter, said first tubular bar extending throughout the machine length and being parallel to the needle bed and arranged with its axis lying substantially in the plane of the needle bed and spaced from the top edge of the latter, a pair of tubular bars externally splined each surrounding a portion of said first bar extending beyond the needle bed and rotatably mounted in the machine frame, a pair of sleeves each mounted axially displaceable but not rotatably on one of said splined bars, a pair of oppositely threaded screws parallel to said bars and each extending substantially over the length of said splined bars, a holder carrying a needle reducing unit attached to the end of each sleeve facing the cross-middle plane of the machine and a nut fast with said sleeve engaging one of said screws, each of said needle reducing units comprising a slide member mounted slidably in a direction perpendicular to the axis of said bars towards and away from the needles upon rotation of said first tubular bar and points capable of engaging the needles in order to take up the loops carried by the latter upon rotation of the said holder, extending parallel to the direction of the displacement of the said member, spaced similarly to the needles of the needle bed and having slits of a width such as to be capable of encircling the needle hooks, a top slide carried by said holder and mounted in the latter displaceable parallel to said supporting structure, a sinker bar carried by said top slide and spikes on said sinker bar turned towards said points and lying in planes extending between the latter; means being provided for controlling the displacements of said supporting structure and of said top slide by rotations of said first tubular bar and further driving means for rotating the latter, the splined bars and said oppositely threaded bars in a proper sequence, in a proper direction and by a proper extent in order to effect taking up of the loops from a number of the needles of the bed by said points and transfer said loops to an equal number of the bed needles shifted with respect to said first-mentioned needles toward the machine middle cross plane.

6. In a fiat bed knitting machine as set forth in claim 5, each of said needle reducing units comprising a pinion mounted axially slidable but not rotatable on said first tubular bar, said slide member provided with a rack meshing with said pinion, a forward plate on said slide member and a set of points spaced similarly to the needles on the needle bed and formed near their ends with slits of a width such as to be capable of engaging the needle I hooks, a top slide mounted in said holder displaceable in a direction parallel to the movements of said slide member provided with a rack, a sinker bar fast with said top slide bent downwardly in a direction perpendicular to said points, a set of spikes projecting from said sinker bar towards the plane containing said points and each arranged in a plane extending between the points, and a lost motion connection between said slide provided with a rack and said top slide, said connection comprising a pin fast with said slide provided with a rack and projecting into a longitudinal slot cut in said top slide.

References Cited by the Examiner UNITED STATES PATENTS 3,159,014 12/1964 Imon 6670 DONALD W. PARKER, Primary Examiner.

P. C. FAW, Assistant Examiner. 

1. IN A FLAT BED KNITTING MACHINE HAVING A STATIONARY FRAME AND AT LEAST ONE NEEDLE BED, AN AUTOMATIC DECREASING DEVICE COMPRISING FOR EACH BED A FIRST TUBULAR BAR ROTATABLY MOUNTED IN SAID STATIONARY FRAME NEAR THE OPPOSITE END OF THE LATTER, SAID FIRST TUBULAR BAR EXTENDING THROUGHOUT THE MACHINE LENGTH AND BEING PARALLEL TO THE NEEDLE BED AND ARRANGED WITH ITS AXIS LYING SUBSTANTIALLY IN THE PLANE OF THE NEEDLE BED AND SPACED FROM THE TOP EDGE OF THE LATTER, A PAIR OF TUBULAR BARS EXTERNALLY SPLINED EACH SURROUNDING A PORTIONK OF SAID BAR EXTENDING BEYOND THE NEEDLE BED AND ROTATABLY MOUNTED IN THE MACHINE FRAME, A PAIR OF SLEEVES EACH MOUNTED AXIALLY MOVABLE BUT NOT ROTATABLY ON ONE OF SAID SPLINED BARS, A PAIR OF OPPOSITELY THREADED SCREWS PARALLEL TO SAID BARS EACH EXTENDING SUBSTANTIALLY OVER THE LENGTH OF ONE OF SAID SPLINED BARS, A HOLDER CARRYING A NEEDLE REDUCING UNIT ATTACHED TO THE END OF EACH SLEEVE FACING THE CROSSMIDDLE PLANE OF THE MACHINE AND A NUT FAST WITH SAID SLEEVE AND ENGAGING ONE OF SAID SCREWS, EACH OF SAID NEEDLE REDUCING UNITS CARRIED BY SAID HOLDER COMPRISING A SUPPORTING STRUCTURE CARRIED BY SAID HOLDER AND CAPABLE OF DISPLACEMENT IN A DIRECTION PERPENDICULAR TO THE COMMON AXIS OF THE SLEEVE AND OF SAID BARS, A SET OF POINTS CARRIED BY SAID SUPPORTING STRUCTURE, DRIVING MEANS FOR ROTATING SAID FIRST TUBULAR SHAFT, SAID SPLINED SHAFTS AND SAID THREADED SHAFT AT PROPER TIMES, IN PROPER SEQUENCE IN A PROPER DIRECTION AND BY A PROPER ANGULAR EXTENT IN ORDER TO TAKE UP THE LOOPS FROM THE NUMBER OF NEEDLES AND TRANFER SAID LOOPS TO AN EQUAL NUMBER OF NEEDLES SHIFTED WITH RESPECT TO SAID FIRST-MENTIONED NEEDLES TOWARD THE MACHINE MIDDLE CROSS PLANE. 